Model railroad hot-box detector



Dec. 19, 1961 s. N. HOWELL MODEL RAILROAD HOT-BOX DETECTOR Filed July 20. 1959 2 Sheets-Sheet 1 40 4/ INVENTOR jqancr M Howl-1.1..

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ATTORNEYS 5/4/14; CONT/POL 1 SMOKE GE/VERflTOR S. N. HOWELL MODEL RAILROAD HOT-BOX DETECTOR 72am r INVENTOR 78196? M Howe-L ATTORNEYS Filed July 20, -l959 Dec. 19, 1961 attain 3,013,360 Patented Dec. 19, 1961 @hhc 3,013,360 MODEL RAILROAD HGT-BOX DETECTQR Sabert N. Howell, Huntington, N.Y., assignor to Servo Corporation of America, New Hyde Park, N.Y., a corporation of New York Filed July 20, 1959, Ser. No. 823,080 6 Claims. (Cl. 46-243) My invention relates to automatic mechanism having particular utility in the operation of a model railroad or the like. This application is a continuation-in-part of my copending application, Serial No. 493,974, filed March 14, 1955, now Patent No. 2,932,126.

In the operation of full-scale railroads, the development of hot boxes is a perpetual problem and frequently endangers the safety of a. train. This problem is not encountered in the operation of model railroads, but the model-railroad enthusiast demands the utmost in realism.

It is, accordingly, an object of the invention to provide model-railroad equipment with improved features of realism.

It is another object to provide means for simulating, on a model railroad, hot-box conditions as encountered in full-scale railroad operation.

it is a further object to provide automatically operated means responsive to the detection of simulated hot-box conditions for controlling train operation.

it is a specific object to meet the above objects with a regulated heat source mounted on a model-railroad vehicle and with automatically controlled smoke-generating means discharging smoke in the vicinity of a simulated hot-box.

Other objects and various further features of novelty and invention will be pointed out or will occur to those skilled in the art from a reading of the following specification in conjunction with the accompanying drawings. In said drawings, which show, for illustrative purposes only, preferred forms of the invention:

FIG. 1 is a side view in elevation of a model-railroad car equipped with devices of the invention and mounted on a track that is monitored With a device of the invention;

FIG. 2 is an end view of the combination of FIG. 1;

FIG. 3 is a perspective view of the wheel relation for the vehicle of HG. 1, the main frame of the vehicle being merely shown in phantom, in order better to display the coordinated functioning of parts of the invention;

FIG. 4 is a perspective view of a truck incorporating features of the invention and representing a modification of the arrangement of FIG. 3;

FIG. 5 is a sectional View through one of the axles of the truck of FIG. 4;

FIG. 6 is a View similar to FIG. 4, but illustrating a further modification;

PEG. 7 is a view of a model-railroad train incorporating features of the invention and representing a modification of the arrangement of FIG. 1;

FIG. 8 is a sectional view of trackside-mounted equipment in FIG. 1;

FIGS. 9 and 10 are circuit diagrams representing alternative modes of utilizing trackside-mounted equipment; and

FIGS. 11 and 12 are simplified electrical diagrams schematically showing alternative vehicle-carried arrangements of the invention.

Briefly stated, my invention contemplates realistic simulation on model-railroad scale, of hot-box conditions of the type which have for years plagued full-scale railroad operators. The simulator comprises a heat source and a smoke generator, so localized as to produce heat and smoke effects uniquely identifiable with a particular journal box on a whole train. My novel equipment includes trackside-mounted heat-responsive means capable of developing an electrical signal upon the detected passage of the simulated hot box, and automatic controls function in response to detection of the hot box. These automatic controls may govern remote signals to display appropriate warnings to the oncoming train and may cut off power to the train.

Referring to FIGS. 1 and 2 of the drawings, my invention is shown in application to a freight car 10 having a pair of trucks .1112 p-ivotally supported at the ends of the car. The car rides a section 13 of electrified track. and alongside the track is mounted detector means 14 of the invention.

Simulation equipment for a hot box, as on the journal end 15, may comprise a localized heat source, eifectiveiy a point source, such as a small coil 16 of resistance wire mounted inconspicuously in the vicinity of the journal end 15. The coil 16 is shown carried by the truck frame, but it will be understood that in certain applications suflicient realism will be achieved if the coil 16 is mounted underneath the frame of the car it Simulation equipment further includes a smoke generator, schematically designated by the dashed outline 17 and carried within the car 19. The smoke generator is shown to be of the variety which consumes fluid, and thus the generator 17 includes a filler pipe 1i; and cover 19; depending on the type of smoke generator 17 used, electricheating means therefor (not shown) may be supplied by the collector means to be described, as will be understood. In order not to spoil the realism, the filler-pipe cover 19 may be in the form of a removable hatch, as of the type used on refrigerator cars; other types of cover will be understood to be desirable for other types of cars. The smoke generator may be connected to the desired discharge location 26 by means of a conduit 21 including flexible material so as to permit pivotal movement of the truck as the car is accommodated on track of varying curvature.

In FIG. 3, the car frame on which my simulator equipment is mounted includes collector means deriving electrical voltage from the track. For the form shown, the track is assumed to be of the two-rail variety in which the two rails are oppositely polarized. Thus, the forward truck 23 and the rear truck 24 may be duplicates of each other, and since they face in opposite directions, the respective trucks will reflect polarity of the respective rails on which they ride; the connections of trucks 2324 to the car 10 should include provision for mutual insulation of trucks 23-24, as by forming the car frame of plastic.

Collector trucks of the character indicated are familiar to those skilled in the art, and it suflices here to say that polarity of voltage collection is achieved by having the wheels 25 on one side of one truck conductive, and the wheels 26 on the other side of said truck nonconductive; in the case of truck 24, wheels 27 will be conductive, and wheels 28 non-conductive. The truck 23 in FIG. 3 is shown equipped with the heat source 16, secured as by a suitable cement, over the journal box 15, and electrical connection thereto is made by flexible means 29 connected to the truck 24, and means 30 connected to the truck 23. With this arrangement, the source 16 will develop heat as long as voltage is supplied to the track.

The smoke-simulating means in FIG. 3 may simply comprise a duct or conduit system discharging at 31 and having a supply connection 32 near the pivotal suspension for the truck. The connection 32 may be flexibly coupled by means 21 to the generator 17, or it may be connected to a smoke generator in a locomotive, as will appear from the discussion below in connection with FIG. 7.

In FIGS. 4 and 5, I show a modification in which the hot-box source simulator may be built into a single truck and thus may be applied simply to any desired model-railroad vehicle with minimum adaptation. The truck of FIGS. 4 and 5 comprises a frame with side members 35-36, connected by cross-member means 37, and the heat source 16 may be mounted near the journal box 15. For a two-track electrical system as described in connection with FIG. 3, the insulating wheel 38 (stippled shading) and the conductive wheel 39 for one axle are connected in opposition to the insulated wheel 46 (stippled shading) and conducting wheel 41 of the other axle. The side members 35-36 may be conductive, but their connection by way of member 37 includes means for mutual insulation, as by fabricating the connecting member 37 of plastic. An insulating cup or bushing 4?. on side member 36 (for the axle of wheels 46-41) and a similar bushing (not shown) on side member 35 (for the axle of wheels 38-39) assure that the side members 35-36 will collect with opposite polarity, so that electrical connections (-43) to the coil 16 may simply be made to the respective side-frame members -36, as will be understood.

In FIG. 6, I show a further modification for the case of so-called three-track electric trains in which a center shoe 44 is polarized with respect to the rest of the frame 45 of the truck. In that event, the coil 16 may be merely connected at 30 to the frame 45 and at 43' to the shoe 44.

In FIG. 7, I show that a car, such as described at 10 in FIG. 1, need not carry its own smoke-generating device, but may use the smoke developed by the generator 46 in a locomotive 47 of otherwise conventional construction. A single flexible conduit 48 may connect the generator 46 with the discharge opening 20 adjacent the simulated hot box; alternatively, each one of the vehicles 49-50-51 (between the locomotive 47 and the car 10) may be provided with separate through-conduits, removably flexibly connected to each other, as will be understood. Depending upon the amount of smoke desired from the discharge opening 20, the locomotive smoke stack 52 may be plugged or not.

In FIG. 8, I show, in simplified form, the basic elements of a trackside detector 14; said detector may comprise one or more heat-sensitive cells 53-54 suitably mounted on means 55 within the head of the device. The head or housing is shown to be generally cup-shaped, with an opening facing transverse to the track so that the elements 53-54 may look for possible hot boxes, the spacing of elements 53-54 being longitudinal in the sense of the course of the track. A window 56 may close the housing and be of a material to transmit infrared radiations. Such material may be arsenic-trisulfide glass, and the heatdetecting elements 53-54 may be metallic-oxide flakes of the variety known as thermistor flakes. The assembly is shown to be completed by provision of two further heat-sensitive elements 57-58, shielded from the radiations to which the elements 53-54 are exposed and serving, therefore, to establish ambient references for operation of the elements 53-54.

In FIG. 9, I show an automatic control circuit involving a simplified trackside detector comprising but one cell element 60 (corresponding to one of the elements 53-54 of FIG. 8) exposed to or facing the hot box to be detected; the shielded cell 61 (corresponding to one of the elements 57-58) is so designated by means of the phantom line 62. The elements 60-61 may be bridge-connected and polarized, as by a D.-C. supply, suggested by the polarity legends in the drawing. The differential output of the exposed and unexposed cells is shown supplied to amplifier means 63, thence to relay means 64. The relay means 64 is shown controlling the application of supply voltage from source 65 to trainvoltage-control means 66, having manual means 67 for varying the voltage and therefore the speed of the train. The arrangement is such that when a beat signal of sufficient magnitude is detected, relay 64 will operate to break the circuit to the train-voltage control 66 so as immediately to stop the train. If desired, a connection, suggested at 68, may be made to trackside-mounted signalling equipment (not shown) so as to enhance the reaiism of the operation by making it appear that the train is warned by the signal before actually stopping.

In the arrangement of FIG. 10, the automatic control of the train is somewhat refined by employing the twincell configuration discussed in connection with FIG. 3. Each of the cells 53-54 is bridge-connected with its compensator cell 57-58 and separately supplies amplifier means 70-71. The amplifier 71 is connected to operate the coil 72 of a first relay, and the amplifier 70 is connected to operate the coil 73 of a second relay. The single contact arm 74 of the relay 73 is normally closed and is in series with the connection of amplifier 71 to coil 72; relay 72 includes two contact arms 75-76, of which arm 76 is normally closed and is in series with the connection of amplifier 70 to coil 73, and arm 75 (to the track-excitation circuit) is normally closed. Both relays 72-73 are preferably of the delay dropout variety, meaning that, once actuated, there is a delay, e.g. of the order of one second, before the actuated relay returns to its normal or unactuated condition. This means that for a train proceeding in the direction to excite cell 53 before cell 54, relay 73 will remain actuated (for the delay drop-out period) to assure that subsequent excitation of cell 54 will not actuate relay 72; in like manner, for a train proceeding in the opposite direction (exciting cell 54 before 53), relay 72 will remain actuated (for the delay drop-out period) to assure that subsequent excitation of cell 53 will not actuate relay 73. If relay 73 is operated for a given passage of the train, the voltage control 67 remains unaffected, but upon operation of relay 72, arm 75 is operated to cut ofi the train voltage and thus stop the train.

The arrangement of FIG. 10 will be seen as a means for operating the train-voltage control and thus for stopping the train (or for operating a remote-signal mechanism 63) only in response to passage of a train in the desired direction along the track. This means that if the car 10 of FIGS. 1 or 7 were turned around so that the hot-box simulator 16 were on the other side, that is, on the side remote from the detector unit 14, the passage of the car in that direction would fail to operate the circuit of FIG. 10, even though the heat developed by the source 16 were sufficient to generate heat signals in both of cells 53-54.

The arrangements of FIGS. 9 and 10 lend themselves to automatically recycling operation, as for use of the railroad and hot-box simulator in a commercial-demonstration exhibit. In FIG. 10, I show adaptation to such purposes by providing a further normally open contact arm 77 under the control of coil 72. Thus, when coil 72 operates to stop the train, a self-resetting time-delay circuit breaker 78 will function (in response to contact at arm 77) to maintain coil 72 energized after heat-signal actuation of coil 72. The length of time coil 72 remains energized will depend on the length of time the train is to be held stopped. After lapse of such time, means 78 will automatically break the circuit to coil 72 and will allow the train to start, whereupon means 73 automatically resets for the next cycle of operation.

In FIG. 11, I show schematically an integrated structure comprising smoke-generator means 17 and the heat source 16 and adaptable to be wholly carried by a single vehicle, such as the car 10. The heat source 16 is shown continuously connected to the respective poles 80-81 of the collector means so that, as described above, the source 16 will emit heat only while voltage is supplied to run the train. I show the further provision of a self-resetting time-delay circuit maker 82 operating from the collected voltage and serving to supply to smokecontrol means 82 a suitable voltage for determining the discharge of smoke only at a predetermined time following initial energizing of the heat source 16. The smokecontrol means 83 is shown to include a simple valve 84 and coil 85 arranged to open the valve 84 only when a prescribed time interval has elapsed after the train has started to run. When the train has stopped, the function of the time-delay means 82 is to reset itself and to close the valve 8 thus, on a subsequent starting of the train, it will be necessary for the same delay to lapse before smoke is discharged. With this arrangement, it is possible to simulate gradual development of a hot-box condition, enabling automatic detection before attainment of a temperature which would cause smoke.

Devices as at 78 and $2. are old in the art and are available from numerous commercial sources, therefore no need is seen for encumbering the specification with further details. In application to FIG, 11, for example, such a device would commence operating at 82' as soon as the circuit to the track is energized. This means that the heat source 16 begins to warm up and the timing cycle begins. After the predetermined delay, the circuit coil 85 is closed.

In the arrangement of FIG. 12, both the generation of heat and the discharge of smoke are applied on a delayed basis, and parts corresponding to those of FIG. 11 are given the same reference numerals. The only difference between FIGS. 11 and 12 is the circuit connection to the heat source 16 so as to establish delayed generation of heat and delayed discharge of smoke. With this arrangement, it is possible to simulate development of a hot-box condition only after the train has been run for the desired delay interval.

It will be seen that I have described relatively simple mechanism for increasing the realism of a model railroad by simulating not only the heat but also the smoke associated with a hot-box condition. My mechanism functions automatically in response to the heat developed (and not to the smoke) and thus simulates the function of a full-scale hot-box detector. My device lends itself to the critical demands of the hobbyist and to commercial demonstrations of the functioning of a full-scale device.

While I have described the invention in detail for the preferred forms shown, it will be understood that modifications may be made within the scope of the invention as defined in the claims which follow.

I claim: I

l. in a model railroad, a track, electrical supply means connected to said track for energizing said track, vehicle means on said track including a driving motor deriving electrical control from said track, said vehicle means having a plurality of axles and a source of infrared radiation localized and externally exposed on one side of said vehicle means in the vicinity of one end of one axle, a trackside heat detector fixedly mounted alongside saidtrack and responsive in a direction toward the track, said heat detector including an element producing an electric output signal in response to said infrared radiation when in the directional response field of said detector, and means responsive to a heat signal in said detector and in controlling relation with said supply means to reduce the driving speed of said motor. 7

2. In combination, supply means including an electrified track, electrically driven vehicle means on said track and deriving electrical energy from said track, said vehicle means including a plurality of wheeled axles journalled therein, a. heat source carried by said vehicle means and locally externally exposed near one end of one of said axles, a track-side heat detector fixedly mounted alongside said track and responsive in a direction toward the track and at an elevation to scan said source during i passage of said vehicle means, and drive-control means for said vehicle means and responsive to detection of the passage of said source by said detector to reduce the electrical supply to said track, whereby the speed of said vehicle means is reduced.

3. The combination of claim 2, in which said lastdefined means interrupts the electrical supply to said track.

4. The combination of claim 2, in which said lastdefined means includes delay-operated means for restarting said vehicle means upon lapse of a given period of time following the heat-controlled stoppage of said vehicle means.

5. In a model railroad, a track, electrical supply means connected to said track for energizing said track, vehicle means on said track including a driving motor deriving electrical control from said track, said vehicle means having a plurality of axles and a source of infrared radiation localized and externally exposed on one side of said vehicle means in the vicinity of one end of one axle, a track-side heat detector fixedly mounted alongside the track and including two laterally spaced electrical heatresponsive elements directionally responsive substantially transverse to the track, each said element producing an electrical output signal in response to said infrared radiation when in the directional response field of said heat detector, first control means responsive to one exclusive of the opposite time sequence of electrical signal outputs from said heat-responsive elements and connected to said electrical supply means to reduce the supply of electrical current to said track, and second control means responsive to said opposite exclusive of said one time sequence of electrical signal outputs from said heat-responsive elements to temporarily prevent operation of said first control means; whereby for passage of an electric train operating on said track and exhibiting a heat condition to which said elements respond, the speed of said train will be automatically reduced for passage of said elements in one direction, but said speed Will be unimpaired for passage of said elements in the opposite direction.

, 6. In a model railroad, a track, electrical supply means connected to said track for energizing vehicle means on said track including a driving motor deriving electrical control from said track, said vehicle means having a plurality of axles and a source of infrared radiation localized and externally exposed on one side of said vehicle means in the vicinity of one end of one axle, track-side heat-detector means fixedly mounted alongside said track and including two laterally spaced electrical heat-detector elements directionally responsive substantially transverse to the track, each said element producing an electrical output signal in response to said infrared radiation when in the directional response field of said detector means, and means responsive uniquely to a unidirectional sequence of heat signals in said elements and in controlling relation with said supply means.

References Cited in the file of this patent UNITED STATES PATENTS 2,002,358 Smith May 21, 1935 2,856,539 Othuber et al Oct. 14, 1958 FOREIGN PATENTS- 940,785 Germany Mar. 29, 1956 

